the logic is that the ldp targeted session is not inside the PW. Is used to establish the PW. The PE routers needs to know which label is the other end PE expecting for this PW.
So based on the "lower layer" mpls (rsvp, or ldp), the PE router has a transport label to reach the opposite end PE (first layer of the stack), and using this targeted session (it doesn't need to be a directly connected router) the PE get the second label to create the stack.
Introduction: The "external-out enable" command is available for
configuration under the "router ospf process" in case of the IOS-XR
operating system. This command basically enables advertisement of
intra-area routes on the device as external routes in th...
IntroductionIn this article we'll discuss how to troubleshoot packet
loss in the asr9000 and specifically understanding the NP drop counters,
what they mean and what you can do to mitigate them. This document will
be an ongoing effort to improve troublesh...